1. Field of the Invention
The present invention relates to an image pickup apparatus.
2. Description of the Related Art
One conventionally known autofocus (“AF”) system equipped in an image pickup apparatus is a contrast type focus detector that sequentially obtains images from an image sensor, and searches for a contrast peak of a subject. In addition, in photographing a person, it is known to extract a face area in a screen and to provide focusing on the extracted face area so as to focus the person to be photographed.
Japanese Patent Laid-Open No. 2007-10898 proposes a method for extracting a face area of a subject through face recognitions of a pan focus process, and for providing a focus control process for the extracted face area in the screen.
However, according to the contrast type focus detection, an image plane moving amount becomes large from the closest end to the infinite end as a focal length of an imaging lens is longer, requiring a longer focus detection time period. In addition, as the focal length of the imaging lens is longer, a depth of field becomes too shallow to provide the pan focus process and the face area cannot be detected with the pan focus process.